W-18 sounds like an abbreviation of JWH-018.
Both drugs are legitimate research chemicals first made in university laboratories by academic chemists. But the similarity ends there.
JWH-018 was the first of a litany of research compounds made in the mid-1990s that ended up in so-called synthetic marijuana products: plant material originally sold as Spice or K2 that was sprayed with chemicals originally intended to understand brain receptors that bind the active molecules in marijuana.
JWH-018 was first made at Clemson University by the laboratory of the now-retired chemistry professor John W. Huffman, PhD. It was one of over 400 molecules that his group made to probe cannabinoid receptors. The rise of synthetic cannabinoid recreational drugs that began in Europe spread to the United States in the late 2000s started with JWH-018.
These synthetic cannabinoids were first valued by marijuana users who were trying to avoid testing positive in urinary drug screens, which were not yet designed to detect that chemical class. The JWH compounds, while they bind to cannabinoid receptors CB1 and CB2 with different affinities, are chemically distinct from THC, the primary psychoactive constituent of marijuana.
Related: W-18, The High Potency Research Chemical, What It Is And What It Is Not
Many of these synthetic cannabinoids turned out to bind the neurochemical receptors in a manner that produced more pronounced effects than THC, particularly feelings of paranoia and anxiety. JWH-018 was among the first five such compounds reassigned to Schedule I of the Controlled Substances Act in 2010.
Forbes contributor Alice G. Walton has a great comparison explainer between synthetic cannabinoids and marijuana.
Since then, later generation synthetic cannabinoids have emerged, such as ADB-FUBINACA, XLR-11, MMB-CHMINACA, and 5F-AMB, among others. Each has its own pharmacology and toxicology but the class remains incompletely studied in humans, primarily because of the paucity of federal research funding. For example, some are known to cause kidney damage, an effect never seen with even high, chronic users of marijuana. So these chemicals clearly have other actions beyond those they're used for recreationally.
W-18 is an entirely different chemical first synthesized at the University of Alberta in the early 1980s. W-18 was among a group of chemicals tested for everything from killing protozoans to relieving pain. Its analgesic activity in an animal model of pain showed that it was 10,000 times more potent than morphine. However, it's not known whether W-18 exerts its painkilling effects via opioid receptors. Hence, its risk to human health is incompletely characterized.
So, in summary, W-18 is a relatively new addition to street drugs derived from sifting of the chemical and patent literature. But it's completely unrelated to JWH-018.
